CN204258686U - Switching magnetic-resistance wind-driven generator direct current exports buck-boost type electrical conversion systems - Google Patents

Abstract

Switching magnetic-resistance wind-driven generator direct current exports buck-boost type electrical conversion systems, comprising: switch reluctance generator and control system, stepping-up/stepping-down chopper circuit, electronic power switch, filter; The input two ends of the stepping-up/stepping-down chopper circuit described in the connection of output direct current positive and negative terminal of described switch reluctance generator and control system thereof, the electronic power switch described in the connection of wherein one end of two outputs of stepping-up/stepping-down chopper circuit, input one end of the filter described in other end connection of electronic power switch, another input of filter connects another output be not directly connected with electronic power switch of stepping-up/stepping-down chopper circuit, and filter exports two ends and connects with other switched reluctance motor systems of wind energy turbine set; The utility model adopts switch reluctance generator to make wind-driven generator, and structure simple direct current output interface chopper circuit, and controllability is strong, especially has certain application value for marine wind electric field field.

Description

Switching magnetic-resistance wind-driven generator direct current exports buck-boost type electrical conversion systems

Technical field

The present invention relates to wind power generation field, especially Oversea wind power generation field, be specifically related to switch reluctance generator (the Switched Reluctance Generator adopting direct output of DC current energy, be called for short: SRG) be wind-driven generator, switch reluctance generator direct current output interface end adopts the system of buck-boost type chopper circuit.

Background technology

Along with the large-scale development of the disposable fossil resources such as oil, coal, the harm that energy crisis and ecological deterioration cause is increasingly serious, and the unique channel that solve this difficult problem is exactly accelerate the exploitation to sustainable resource; In existing regenerative resource, no matter scale, or availability, wind energy is all one of the highest resource, and wind energy is utilizing in process and need not consume mineral resources, not discharge harmful, is considered as cleaning, the energy of green, environmental protection by people.

The area that the one land wind energy resources of Xian Shi China enriches the most from Xinjiang to the Inner Mongol, this area's wind speed is stable, scarcely populated, is well suited for building Large Scale Wind Farm Integration.Over more than ten years, the wind energy development in these regions is very fast, but due to the electricity needs of near zone not high, a large amount of wind-powered electricity generations is difficult to digest nearby; If unnecessary wind-powered electricity generation will be transferred to the huge region of Southeast of electricity needs, the feature that wind electricity volatility is strong can make again difficulty and the cost aggravation of transmission, and threatens to power grid security; And on the other hand, east China seashore line length, wind energy resources is good, wind energy quality is good, possesses the resources supplIes of extensive development offshore wind farm, and mineral resources are deficient, electricity needs is huge, and offshore wind farm can receive nearby, therefore has broad prospects at this regional development offshore wind farm.

Another advantage of wind energy on the sea is that wind speed is higher, wind-force is more lasting, compares with land wind energy, and the wind speed in open marine site wants high 30%-40%, and greater coasting area wants high 15%-20%, can the electric energy of multiple 50%-70%; And the land space that can hold large-scale wind field has at present been difficult to find, the construction of marine wind electric field has become the Main way of Wind Power Utilization.

Although the exploitation of people to wind-powered electricity generation has ISUZU company, mainly concentrate on land, the experience of building marine wind electric field compares shortage; The major defect of offshore wind farm is that to build the cost of pylon and platform (maritime transformer station) in the seawater high, the high in cost of production of maintenance operation, thus to Wind turbines and electric power transfer thereof efficient, stable, reliable request is higher, simultaneously technically also there is different Liquified gas tankers unsteady flow, transmission of electricity etc. are multinomial, particularly, be different from land wind-powered electricity generation, offshore wind farm utilizes HVDC Transmission to become development and application trend, excellent.

Current Wind turbines is mainly based on double-fed asynchronous wind driven generator group with directly drive total power changing type permanent magnet synchronous wind generator group, double-fed asynchronous wind driven generator group has good cost performance, but to the ride-through capability of electric network fault and enabling capabilities more weak, its driving-chain must have large gearbox, and this proposes harsher requirement to the reliability and maintainability of unit; Directly drive total power changing type permanent magnet synchronous wind generator group grid-connected by frequency converter, stronger to the ride-through capability of electric network fault, there is certain support electrical network ability, avoid the maintenance workload of gear box, reliability increases, but because its rotating speed is very low, along with the increase of power, the manufacturing process of multi-pole magneto alternator is complicated, and technical difficulty is large, and motor volume is large, cost is high, Attention problems cost is higher, and simultaneously along with the continuous increase of unit capacity, supporting frequency converter is expensive further increases its use cost.

Switch reluctance generator structure is simple, brushless on rotor, without winding, without permanent magnet; It is equivalent to a current source when running, and like this in certain range of speeds, output end voltage can not change along with the change of rotating speed, and this is very suitable for the wind energy conversion system of the variable-speed operation of current main-stream, can improve the utilization ratio of wind energy; The more important thing is that it directly sends as direct current, adapted to current offshore wind farm carries out electric power transfer trend needs in efficient direct current mode, eliminated rectification link; Due to these characteristics, switch reluctance generator can realize higher generating efficiency under wind-force Direct driver, thus eliminates gear box, makes whole power generation system structure more succinct, reliable, the development trend of this also wind generator system just; And in running, switch reluctance generator controllable parameter is many, as turn-on angle, hold-off angle control, Current cut control etc., the control strategy of more complicated can be realized easily, control output dc voltage and electric current flexibly, also greatly reduce the technostress of low voltage crossing; Visible, switch reluctance generator introduces offshore wind farm, meet the needs installing the offshore wind farm development difficult, cost is high, maintaining is difficult completely, the i.e. high efficiency conversion realizing wind energy, the simplicity of structure means the maintenance that higher reliability is less and lower installation cost and equipment purchase cost.

To switched reluctance machines carry out that the research of electric operation carries out comparatively early, be widely used in electric traction at present, needed four quadrant running governing system and realize in the system of high-efficiency operation in the velocity interval of broadness.But to the research of its generator operation characteristic, until late 1980s just paid attention to, and expand in the applications such as space flight starting/generator exploration research.

Desirable wind turbine generator should be can variable-speed operation, Direct driver, saves gear box, reduces unnecessary maintenance work; Weigh switch reluctance generator accordingly, can find that switch reluctance generator is used for wind power generation and has following concrete advantage: (1) switch reluctance generator has excellent speed adjusting performance, slewing range is wide, can adapt to the requirement of different wind speed, utilize wind energy more efficiently; (2) switch reluctance generator efficiency when low cruise is high, by rational design, can save gear box, realize the generating of wind energy conversion system Direct driver, thus improve the generating efficiency of whole system, improve the annual energy output of wind generator system, reduce cost of electricity-generating; (3) switch reluctance generator manufacture is simple, brushless on rotor, coil, does not need permanent magnetic material (rare earth material) etc., thus simplifies the structure, such that the reliability of motor is high, cost is low; (4) switch reluctance generator is typical electromechanical integrated product, and control is flexible, controling parameters is many, can realize the control strategy of more complicated easily, controls direct voltage and the direct current of output flexibly; (5) switch reluctance generator can send the direct current of voltage constant easily, and output voltage and rotating speed have nothing to do, and directly can be regulated by the controller of self, easily grid-connected during multiple stage generator operation; (6) between switch reluctance generator phase winding without electric coupling, its fault-tolerant ability strengthens greatly, even if when phase shortage, still can maintenance work (more than three-phase); (7) power density of switched reluctance machines is high, and motor volume is little, is easy to installation and transportation, and resistance to elevated temperatures is good, the Jobs on the sea environment of very applicable wind power generation; (8) switch reluctance generator has self-excitation ability, only needs the direct current excitation power supply of low capacity, just can set up operating voltage.In practical application, complementary system can be formed with storage battery, when wind-force is sufficient, switch reluctance generator obtains excitation power supply from storage battery and generates electricity, and after setting up operating voltage, the electric energy sent is powering load on the one hand, charge a battery simultaneously, when wind-force is not enough, the energy storage of storage battery discharges, for load.These features make switch reluctance generator should be suitable for use in very much in the occasion of wind power generation and offshore wind farm above.

In recent years, being used for the research and practice of wind power generation about switch reluctance generator also has, and wherein, patent 1, CN 102223034 B, large-scalely directly drive switching magnetic-resistance wind-driven generator and machine set system thereof, 2013.04.10; 2, CN 101686034 B, based on the maximum power automatic tracking method of Switched Reluctance GeneratorUsed in Wind Energy Converter System, 2012.04.25; 3, CN 102427323 B, switching magnetic-resistance wind power system starts control and MPPT control method, 2013.10.30, respectively with regard to high power density SRG design and system, SRG wind power generation maximum power automatic tracking method and SRG wind power generation startup and maximal power tracing control aspect make progress and patent of obtaining the authorization.

In scientific research circle, about the research of wind-powered electricity generation in conjunction with switch reluctance generator, also mainly focus on unit maximal power tracing aspect, such as: 1, bear stands new etc. a kind of switching magnetic-resistance wind-power generator maximal wind-energy tracking [J]. and electrotechnics journal, 2009,24 (11): 1-7; 2 .Differential evolution method-based output power optimisation of switched reluctancegenerator for wind turbine applications [J] the .IET Renew.Power Gener. such as Hedi Yahia, 2014,8 (7): 795-806; 3 .A Study on the Maximum Power Control Method of Switched Reluctance Generatorfor Wind Turbine [J] the .IEEE TRANSACTIONS ON MAGNETICS such as Da-Woon Choi, 2014,50 (1).

But, with regard to the research of switch reluctance generator system dc output transform or practice seldom.

Domestic and international research shows, adopt high voltage direct current (High-Voltage Direct Current, be called for short: mode transferring electric power HVDC) is the most convenient economical for offshore wind farm, and voltage converter (Voltage Source Converter, be called for short: HVDC (VSC-HVDC) VSC) controls flexibly with it, volume is little, possess the features such as black start-up ability, is particularly suitable for the connection being applied to marine wind electric field and electrical network; The wind field that the existing HVDC of utilization is connected with electrical network all adopts the mode setting up a transformer station at sea, because current offshore power generator is all alternating current generator, the AC transformer that will be connected by every platform alternating current generating sets first boosts to middle pressure, then focus on maritime transformer station and convert direct current conveying to, connect AC network by after the inverter inversion of transformer station on the bank; Its complex structure, electric energy needs through the conversion repeatedly between AC and DC.

The design feature of Wind turbines itself is then considered in some research, directly DC network can be formed after a unsteady flow, by DC parallel network, electric energy is focused on marine DC boosting transformer station, then by direct current transmission ashore transformer station, last another mistake becomes connection AC network, this reduces system complexity, but be only omitted step-up transformer.

Further research shows, directly be connected in series each Wind turbines of direct current then more economically, can without the need to step-up transformer and maritime transformer station, multiple low-pressure air group of motors becomes required high voltage direct current after directly connecting, then be directly transferred to land transformer station by subsea DC cable, this kind of mode has become the study hotspot that marine wind electric field electric energy converges at present.

Summary of the invention

According to above background technology, the utility model, in conjunction with wind energy turbine set especially marine wind electric field, for DC series type wind field structure, proposes the simple buck-boost type transformation system of the unit output electric energy adopting switch reluctance generator as wind-driven generator.

The technical solution of the utility model is:

Switching magnetic-resistance wind-driven generator direct current exports buck-boost type electrical conversion systems, is made up of switch reluctance generator and control system 101 thereof, stepping-up/stepping-down chopper circuit 102, electronic power switch 103, filter 104, its technical characteristic is, the input opposite ends of the stepping-up/stepping-down chopper circuit 102 described in the connection of output direct current positive and negative terminal of described switch reluctance generator and control system 101 thereof, the electronic power switch 103 described in the connection of wherein one end of two outputs of stepping-up/stepping-down chopper circuit 102, input one end of the filter 104 described in other end connection of electronic power switch 103, another input of filter 104 connects another output be not directly connected with electronic power switch 103 of stepping-up/stepping-down chopper circuit 102, filter 104 exports two ends and connects with other switched reluctance motor systems of wind energy turbine set.

Numerous switched reluctance motor system 1a, 1b ... output be all connected in series.

Described stepping-up/stepping-down chopper circuit 102, is made up of the first capacitor C1, the second capacitor C2, the first resistance R1, the second resistance R2, electronic power switch VT, reactor L, Power Diode Pumped VD, the 3rd capacitor C3; its technical characteristic is, described first capacitor C1 is connected the both positive and negative polarity exported from switch reluctance generator and control system 101 thereof up and down respectively after connecting with described second capacitor C2, described first resistance R1 is connected the both positive and negative polarity exported from switch reluctance generator and control system 101 thereof up and down respectively after connecting with described second resistance R2, first capacitor C1 is connected with the middle series connection point of the first resistance R1 and the second resistance R2 with the middle series connection point of the second capacitor C2, first resistance R1, first capacitor C1 relative to the second resistance R2 and the second capacitor C2 is away from the output of input and switch reluctance generator and control system 101 thereof, described electronic power switch VT one end connects the upper end of the first resistance R1 and the output cathode end of switch reluctance generator and control system 101 thereof, the other end of electronic power switch VT connects the negative pole end of described reactor L one end and described Power Diode Pumped VD, the other end of reactor L connects the lower end of the second resistance R2 and the output negative pole end of switch reluctance generator and control system 101 thereof, the positive terminal of Power Diode Pumped VD connects described 3rd capacitor C3 one end and as output one end of stepping-up/stepping-down chopper circuit 102, the lower end of the 3rd capacitor C3 other end linked reactor L and the output negative pole end of switch reluctance generator and control system 101 thereof, also be the other end that stepping-up/stepping-down chopper circuit 102 exports simultaneously.

Electronic power switch 103 is normally closed switch, when switch reluctance generator and control system 101 thereof or stepping-up/stepping-down chopper circuit 102 break down, or when wind-force is too small or excessive needs stop generating, is disconnected by electronic power switch 103.

Major technique effect of the present utility model is:

Switching magnetic-resistance wind-driven generator direct current of the present utility model exports buck-boost type electrical conversion systems, because switch reluctance generator directly sends direct current, eliminate rectification link, simplify the structure and reduce cost and improve reliability, also therefore, the full direct current be only truly based on the direct current transportation wind power plant of switch reluctance generator sends out transmission of electricity; And the advantage of direct current transportation is self-evident, the advantage that especially loss is little, it is also little that the direct current cables that the words under marine wind field environment adopt is layed in the pollution caused in seabed;

Current wind-driven generator is owing to being all almost alternating current generator, and the output of every platform generator adopts first rectification often, then inversion and adopt high frequency transformer boost after again rectification be direct current; Or generator is first step-up transformer boosting after sending alternating current, and then rectification isotype, and the former transformation of electrical energy is complicated, complex structure, and the latter is due to the bulky that exists of low-frequency transformer, and therefore the words of marine wind electric field often need to add to build maritime transformer station; And switching magnetic-resistance wind-driven generator direct current of the present utility model exports buck-boost type electrical conversion systems; structure is simple; compact; cost is low; consider the controllability flexibly that switch reluctance generator itself is unique and the regulating power of translation circuit (stepping-up/stepping-down chopper circuit 102) to voltage itself; and the protective effect of electronic power switch 103 during fault, so can not isolation link be considered.

According to the adjustment of the duty cycle of switching of electronic power switch VT, flexibly changing output dc voltage value, relative input voltage, output voltage adjustable extent is wide, this is another adjustable part after the regulatory function of switch reluctance generator itself, can strengthen the low-voltage crossing of system and antijamming capability and wind field voltage regulation capability; Even if although stepping-up/stepping-down chopper circuit 102 exports relative maximum voltage be also difficult to the bus voltage value energy ratio with high voltage direct current transmission, the high-voltage value that wind field voltage can reach required has then been raised in numerous switched reluctance motor system series connection.

The existence of filter 104, can guarantee the steady of direct voltage and electric current.

Accompanying drawing explanation

Figure 1 shows that offshore wind farm field pattern of the present utility model.

Figure 2 shows that switching magnetic-resistance wind-driven generator direct current of the present utility model exports buck-boost type electrical conversion systems figure.

Figure 3 shows that stepping-up/stepping-down chopper circuit figure of the present utility model.

In figure: 1a, 1b ... 1n represents each switched reluctance motor system, and 2 represent submarine cable, and 3 represent transformer station on the bank, 101 representation switch reluctance generator and control system thereof, 102 represent stepping-up/stepping-down chopper circuit, and 103 represent electronic power switch, and 104 represent filter.

Embodiment

For tandem type marine wind electric field as shown in Figure 1, switched reluctance motor system 1a, 1b ... the switch reluctance generator driven for multiple wind energy conversion system and accordingly control and electrical energy changer, although the direct voltage apparent wind electric field busbar voltage that each switched reluctance motor system exports is low many, but numerous switched reluctance motor system series connection can form high direct voltage, be transferred to transformer station 3 on the bank via submarine cable 2, then be connected with external communication electrical network by after transformer station 3 inversion on the bank.

Switched reluctance motor system 1a, 1b, namely switching magnetic-resistance wind-driven generator direct current output buck-boost type electrical conversion systems comprises switch reluctance generator and control system 101 thereof, stepping-up/stepping-down chopper circuit 102, electronic power switch 103, filter 104, as shown in Figure 2, switch reluctance generator and control system 101 thereof complete and control the conventional control of its own switch reluctance generator and MPPT maximum power point tracking, the lifting that stepping-up/stepping-down chopper circuit 102 realizes voltage is adjustable, the direct current of filter 104 pairs of pre-output carries out the filtering of voltage and current, the effect of electronic power switch 103 disconnects when switched reluctance motor system need be shut down, closed during system cloud gray model.

Figure 3 shows that stepping-up/stepping-down chopper circuit 102, the effect of the first capacitor C1, the second capacitor C2 be switch reluctance generator is directly sent direct current filtering, voltage support, and in emergency circumstances suppress the effect of voltge surge, first resistance R1 and the second resistance R2 then plays the voltage balancing the first capacitor C1 and the second capacitor C2 respectively, protect the voltage uniform of these two capacitors, safety, the effect of simultaneously stability first capacitor C1 and the unnecessary electric energy of the second capacitor C2; The resistance of the first resistance R1 and the second resistance R2 is quite high, should in hundred M Ω ranks, because the larger power loss that causes of the too small meeting of resistance have the possibility of overcurrent.

As shown in Figure 3, electronic power switch VT can be IGBT, or other controlled power electronic device, as thyristor, according to thyristor, need arrange the auxiliary circuit that thyristor turns off.

Require that reactor L and the 3rd capacitor C3 is enough large, make the branch current of reactor L and the 3rd capacitor C3 two ends direct voltage be straight direct current to meet, their excessive pulsatile change must not be had influence on because of corresponding inductance or capacitance when electronic power switch VT switch motion.

When electronic power switch VT is in closed conducting state, stepping-up/stepping-down chopper circuit 102 input direct voltage E to power to reactor L through electronic power switch VT and makes its storage of electrical energy; Until when electronic power switch VT turns off, the electric energy stored in reactor L is to the 3rd capacitor C3 and load release, and for the output of stepping-up/stepping-down chopper circuit 102, its two ends polarity relative input end is just in time contrary; Until when electronic power switch VT goes and closes conducting, except reactor L is by except charging energy-storing, the electric energy stored in the 3rd capacitor C3 of opposite side is at this moment simultaneously as exporting electric energy and maintaining stable magnitude of voltage; Can according to the absorption of reactor L within switch one cycle of electronic power switch VT and release electric energy conservation principle, the output voltage obtaining this stepping-up/stepping-down chopper circuit 102 relative to input voltage along with electronic power switch VT closed conducting and opening time the difference of ratio and different, relative input voltage, can not only step-down and can boosting, adjustable range is wide, to adapt to the regulable control needs during interference such as wind energy turbine set fault or low-voltage crossing.

Claims (3)

1. switching magnetic-resistance wind-driven generator direct current exports buck-boost type electrical conversion systems, is made up of switch reluctance generator and control system (101) thereof, stepping-up/stepping-down chopper circuit (102), electronic power switch (103), filter (104), its technical characteristic is, the input opposite ends of the stepping-up/stepping-down chopper circuit (102) described in the connection of output direct current positive and negative terminal of described switch reluctance generator and control system (101) thereof, the electronic power switch (103) described in the connection of wherein one end of two outputs of stepping-up/stepping-down chopper circuit (102), input one end of the filter (104) described in other end connection of electronic power switch (103), another input of filter (104) connects another output be not directly connected with electronic power switch (103) of stepping-up/stepping-down chopper circuit (102), filter (104) exports two ends and connects with other switched reluctance motor systems of wind energy turbine set.

2. switching magnetic-resistance wind-driven generator direct current according to claim 1 exports buck-boost type electrical conversion systems, it is characterized in that, described stepping-up/stepping-down chopper circuit (102), is made up of the first capacitor (C1), the second capacitor (C2), the first resistance (R1), the second resistance (R2), electronic power switch (VT), reactor (L), Power Diode Pumped (VD), the 3rd capacitor (C3); described first capacitor (C1) is connected with after described second capacitor (C2) series connection the both positive and negative polarity exported from switch reluctance generator and control system (101) thereof up and down respectively, described first resistance (R1) is connected with after described second resistance (R2) series connection the both positive and negative polarity exported from switch reluctance generator and control system (101) thereof up and down respectively, first capacitor (C1) is connected with the middle series connection point of the first resistance (R1) and the second resistance (R2) with the middle series connection point of the second capacitor (C2), first resistance (R1), first capacitor (C1) relative to the second resistance (R2) and the second capacitor (C2) are away from the output of input and switch reluctance generator and control system (101) thereof, described electronic power switch (VT) one end connects the upper end of the first resistance (R1) and the output cathode end of switch reluctance generator and control system (101) thereof, the other end of electronic power switch (VT) connects the negative pole end of described reactor (L) one end and described Power Diode Pumped (VD), the other end of reactor (L) connects the lower end of the second resistance (R2) and the output negative pole end of switch reluctance generator and control system (101) thereof, the positive terminal of Power Diode Pumped (VD) connects described 3rd capacitor (C3) one end and as output one end of stepping-up/stepping-down chopper circuit (102), the lower end of the 3rd capacitor (C3) other end linked reactor (L) and the output negative pole end of switch reluctance generator and control system (101) thereof, also be the other end that stepping-up/stepping-down chopper circuit (102) exports simultaneously.

3. switching magnetic-resistance wind-driven generator direct current according to claim 1 exports buck-boost type electrical conversion systems, it is characterized in that, described electronic power switch (103) is normally closed switch, when switch reluctance generator and control system (101) thereof or stepping-up/stepping-down chopper circuit (102) break down, or when wind-force is too small or excessive needs stop generating electricity, electronic power switch (103) is disconnected.